The research to be performed during the period covered by this proposal will be concerned with an analysis of the structural proteins of rubella virus. The first objective is to purify the viral proteins from infected cell lysates and from purified virus. Each purified protein will be subjected to chemical characterization using such parameters as molecular weight determinations, polypeptide chain analysis and amino acid analysis. In addition, each purified protein will be analyzed for the ability to elicit the production of neutralizing antibody in the host animal. The method of synthesis of rubella proteins in the infected cell will also be analyzed to determine if the rubella genome is translated as a monocistronic message or if this virus exerts translational control. It is anticipated that the research proposed here will provide the basis for a continuing study of assembly and maturation.